Velux sizes: logic vs their recommendation??

[eros_poli]

Hey

 

We're planning (and nearly ready to build) a two storey extension. The top floor will be vaulted ceiling, two velux's, two windows, open plan. 

 

Velux recommend "In general, we recommend that the size of your roof window should be at least 20% of your room's floor area."

 

This would put our two Velux's at 1.9m2 each (closest size being UK08, 1.34m x 1.4m) - those seem enormous when taping them out.... 

 

The room (plan attached) will have a window on the NE side, and a window on the NW side, as well as light coming from a small window and small velux in a semi-hallway on the SSW side. The room is approx 19m2. 

 

Any thoughts? We can save a chunk of cash down sizing these units (MK06 for example, 78cm x 1.18m, which still seem very large). 

 

Thanks

 

Joe

Edited November 22 by eros_poli

[DevilDamo]

780mm wide units will be fine for that room.

 

How have the two Bedroom windows been set out as they don’t align with one another at all? You may not want that but it’s something you’d notice quite a bit inside the room.

 

Where are your wardrobes going as the current layout and positioning of windows doesn’t make that easy?

 

Why isn’t the En-suite just all at the same angle as the main walls? If you’re wanting to avoid a narrow corridor feel to the main Bedroom, you could introduce an angle or curve on the En-suite wall.

[DevilDamo]

Just some more comments…

 

- Where is the door to Bedroom 1?

- I assume the door to the En-suite will be a normal door as the FD reference usually indicates a fire door, but in this instance may refer to a “first floor door”?

- How does the foul water from the W.C. connect to the SVP with all the stud work framing in place?

[torre]

I think that 20% is more of a guide where velux are the only source of daylight.

 

In your case, with other windows smaller roof lights should be absolutely fine, try to work out the overall window area as a percentage (as a point of reference building regs for a new build generally don't allow more than 25% window to floor area)

 

You could probably save money embracing the wedge shape of your ensuite instead of so much studwork but that very much a personal design decision

[eros_poli]

Thanks for the comments @DevilDamo and @torre

 

Think we'll go some some smaller units as the room should be plenty bright enough. 

 

Torre yes the additional stud work was added by the chap who did the drawings, we're very much going to embrace the odd angles and not box anything out. It's linked to a very wonky old cottage which has no straight lines! 

 

@DevilDamo all has been thought through in great detail already, thanks for the thoughts  

[Mr Punter]

There are quite a few windows up there so I am unsure why you need the rooflights.  They are far less thermally efficient than a properly insulated roof and can cause unwanted solar gain.  They also take up space that could be used for PV.

[DevilDamo]

8 hours ago, eros_poli said:

all has been thought through in great detail

You must be working to a different drawing then. Good luck!